Determining if an array supports automated unmap in vSphere 6.5

Many of you will be aware of the new core storage features that were introduced in vSphere 6.5. If not, you can learn about them in this recently published white paper. Without doubt, the feature that has created the most amount of interest is automated unmap (finally, I hear you say!). Now a few readers have asked about the following comment in the automated unmap section. Automatic UNMAP is not supported on arrays with UNMAP granularity greater than 1MB. Auto UNMAP feature support is footnoted in the VMware Hardware Compatibility Guide (HCL). So where do you find this info in…

Some upcoming speaking engagements

A short post to let you know about some upcoming speaking engagements that I am doing over the next couple of weeks. First up, I will be speaking at the TechUG, or Technology User Group event next week. This event will be held on Thursday, November 26th. It will be held in the Westin Hotel in the heart of Dublin city, Ireland. There is a really good agenda for this event (which is not a VMware centric event), that you can find at this link here. I personally will be speaking about Virtual SAN (VSAN), VMware’s hyper-converged compute and storage…

VAAI now available with vSphere Standard Edition

A short post today, but it highlights what I feel is an important enhancement to vSphere licensing. I’ve had lots of questions recently about why VAAI (Storage APIs for Array Integration) is not available in the standard edition of vSphere. This is especially true since I began posting about Virtual Volumes earlier this year, and it was clear that Virtual Volumes is available in the standard edition. One reason why this was confusing is that if a migration of a VVol could not be handled by the array using the VASA APIs, the migration would fall back to using VAAI…

vSphere 6.0 Storage Features Part 8: VAAI UNMAP changes

A few weeks, my good pal Cody Hosterman over at Pure Storage was experimenting with VAAI and discovered that he could successfully UNMAP blocks (reclaim) directly from a Guest OS in vSphere 6.0. VAAI are the vSphere APIs for Array Integration. Cody wrote about his findings here. Effectively, if you have deleted files within a Guest OS, and your VM is thinly provisioned, you can tell the array through this VAAI primitive that you are no longer using these blocks. This allows the array to reclaim them for other uses. I know a lot of you have been waiting for…

vSphere 6.0 Storage Features Part 7: VAAI XCOPY improvements

The more astute of you who have already moved to vSphere 6.0, and like looking at CLI outputs, may have observed some new columns/fields in the PSA claimrules when you run the following command: # esxcli storage core claimrule list –claimrule-class=VAAI The new fields are as follows (slide right to view full output): XCOPY Use Array XCOPY Use XCOPY Max Reported Values  Multiple Segments  Transfer Size ————— —————–  ————– false                   false                  0 false                   false                  0 false                   false                  0 false                   false                  0 false                   false                  0 false                   false                  0 false                   false                  0 false                   false                  0 false                   false                  0 false                  false                  0 false                  …

Heads Up! ATS Miscompare detected between test and set HB images

I’ve been hit up this week by a number of folks asking about “ATS Miscompare detected between test and set HB images” messages after upgrading to vSphere 5.5U2 and 6.0. The purpose of this post is to give you some background on why this might have started to happen. First off, ATS is the Atomic Test and Set primitive which is one of the VAAI primitives. You can read all about VAAI primitives in the white paper. HB is short for heartbeat. This is how ownership of a file (e.g VMDK) is maintained on VMFS, i.e. lock. You can read…

Migrations and Virtual Volumes – Deep Dive

Recently I published an article on Virtual Volumes (VVols) where I touched on a comparison between how migrations typically worked with VAAI and how they now work with VVols. In the meantime, I managed to have some really interesting discussions with some of our VVol leads, and I thought it worth sharing here as I haven’t seen this level of detail anywhere else. This is rather a long discussion, as there are a lot of different permutations of migrations that can take place. There are also different states that the virtual machine could be in. We’re solely focused on VVols…